Substrate processing chamber with dielectric barrier discharge lamp assembly

ABSTRACT

A thermal processing chamber with a dielectric barrier discharge (DBD) lamp assembly and a method for using the same are provided. In one embodiment, a thermal processing chamber includes a chamber body and a dielectric barrier discharge lamp assembly. The dielectric barrier discharge lamp assembly further comprises a first electrode, a second electrode and a dielectric barrier. The dielectric barrier discharge lamp assembly is positioned between the first electrode and the second electrode. The dielectric barrier defines a discharge space between the dielectric barrier and the second electrode. A circuit arrangement is coupled to the first and second electrodes, and is adapted to operate the dielectric barrier discharge lamp assembly.

CROSS-REFERENCE TO OTHER APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 11/380,553, entitled “SUBSTRATE PROCESSING CHAMBER WITHDIELECTRIC BARRIER DISCHARGE LAMP ASSEMBLY”, filed Apr. 27, 2006, nowU.S. Pat. No. 7,978,964 which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a semiconductor processingtool and, more specifically, to a thermal processing tool havingdielectric barrier discharge lamp assembly.

2. Description of the Related Art

Rapid thermal processing (RTP) is a process for annealing substratesduring semiconductor fabrication. During this process, thermal radiationis used to rapidly heat a substrate in a controlled environment to atemperature of up to and beyond nine hundred degrees Celsius. Thistemperature is maintained for a specific amount of time ranging fromless than one second to several minutes, depending on the process. Thesubstrate is then cooled before further processing.

Conventionally, RTP chambers typically include radiant heat sources orlamps, a chamber body and a substrate support assembly. The substratesupport assembly is disposed in the chamber body and supports asubstrate while processing. The radiant heat sources are typicallymounted to a top surface of the chamber body or embedded in the interiorwalls of the chamber so that the radiant energy generated by the sourcesimpinge upon the substrate positioned on the substrate support assembly.A quartz window is typically disposed in the top surface of the chamberto isolate radiant heat sources and the interior process region wherethe substrate typically disposes in the process chamber.

The radiant energy generated by the lamp is in the form of a wave ofthermal radiation. The radiation is broadband and typically has a peakwavelength of around 800 nm to around 1500 nm. During transmissionthrough the quartz window to the substrate surface, a portion of theradiant energy may be lost. For example, wavelengths longer than about4000 nm are not transmitted. The quartz window thus causes a change inwavelength of the radiation energy passing therethrough, which now maybe between about 400 nm to about 4000 nm, or even higher, and into theinfrared region (IR). These wavelengths of radiant energy areinsufficient to drive photochemical reactions on the substrate surfaceand may further result in an insufficient number of generated reactivespecies being available to react and form a bulk film on the substrate.

Therefore, there is a need for an improved lamp assembly for use in athermal processing chamber.

SUMMARY OF THE INVENTION

A thermal processing chamber with a dielectric barrier discharge (DBD)lamp assembly and a method for using the same are provided. In oneembodiment, a thermal processing chamber includes a chamber body and adielectric barrier discharge lamp assembly. The dielectric barrierdischarge lamp assembly further comprises a first electrode, a secondelectrode and a dielectric barrier. The dielectric barrier dischargelamp assembly is positioned between the first electrode and the secondelectrode. The dielectric barrier defines a discharge space between thedielectric barrier and the second electrode. A circuit arrangement iscoupled to the first and second electrodes, and is adapted to operatethe dielectric barrier discharge lamp assembly.

In another embodiment, the thermal processing chamber includes a chamberbody defining an interior volume and a substrate support assemblydisposed in the interior volume of the chamber body. A radiant heatassembly is positioned to direct radiation towards the substrate supportthrough a window formed through the chamber body. A dielectric barrierdischarge lamp assembly positioned between the radiant heat assembly andthe substrate support, the dielectric barrier discharge lamp assemblyadapted to radiate the interior volume of the chamber body.

In yet another embodiment, a method for processing a substrate includespositioning a substrate on a substrate support assembly disposed in aprocess chamber, exposing the substrate to a radiation energy generatedby a radiant heat assembly, and exposing the substrate to a secondradiation energy generated by a dielectric barrier discharge lampassembly.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a sectional perspective view of one embodiment of a thermalprocessing chamber with dielectric barrier discharge assembly;

FIG. 2 is another sectional perspective view of one embodiment of athermal processing chamber with dielectric barrier discharge assembly;

FIG. 3 is a sectional perspective view of another embodiment of athermal processing chamber with dielectric barrier discharge lampassembly;

FIG. 4 is a sectional perspective view of one embodiment of a thermalprocessing chamber with internal isolated dielectric barrier dischargelamp assembly;

FIG. 5 is a sectional perspective view of another embodiment of athermal processing chamber with internal isolated dielectric barrierdischarge lamp assembly; and

FIG. 6 is a sectional perspective view of another embodiment of athermal processing chamber with dielectric barrier discharge lampassembly with a heat assembly disposed in the substrate support.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

It is to be noted, however, that the appended drawings illustrate onlyexemplary embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Embodiments of present invention provide an apparatus and method forgenerating a combined IR and UV radiant energy in a thermal processingsystem. The combined radiant energy is utilized to promote photochemicalreactions on the substrate surface, thereby allowing uniform thermalprocessing on the substrate. The combined radiant energy is obtainedusing a dielectric barrier discharge (DBD) lamp assembly in a thermalprocessing system, which advantageously facilitates efficient anduniform substrate processing.

FIG. 1 is a simplified sectional perspective view of one embodiment of arapid thermal processing chamber 100 having a dielectric barrierdischarge (DBD) lamp assembly 150. Examples of rapid thermal processingchambers that may be adapted to benefit from the invention are XEplusand RadiancePlus™ CENTURA® thermal processing system, both availablefrom Applied Material, Inc., located in Santa Clara, Calif. Although thedielectric barrier discharge lamp assembly 150 is described as utilizedwithin the illustrated rapid thermal processing chamber 100, thedielectric barrier discharge lamp assembly 150 may be utilized in otherthermal processing systems, such as deposition chambers, etch chambers,and photo-exposure chambers, among others.

The processing chamber 100 includes a chamber body 102 having chamberwalls 104, a bottom 110, and a top 112 defining an interior volume 120.The walls 104 typically include at least one substrate access port 148to facilitate entry and egress of a substrate 140. A quartz window 114is included in a radiant heat assembly 106 mounted to the top 112 of thechamber body 102. The radiant heat assembly 106 is utilized to heat thesubstrate 140 positioned in a substrate support 108. The radiant heatassembly 106 includes a plurality of lamp tubes 160 in a water jacketassembly 162. Each tube 160 contains a reflector and a tungsten halogenlamp assembly. The lamp tubes 160 are rested in a honeycomb light pipearrangement. This close-packed hexagonal arrangement of light pipesprovides radiant energy, such as an IR radiation and/or longerwavelength of UV radiation having a wavelength between about 400 nm andabout 4000 nm with high-power density. In one embodiment, the radiantheat assembly 106 provides radiant energy to thermally process thesubstrate, such as annealing a silicon layer disposed on the substrate140. One radiant heat assembly 106 that may be adapted to benefit fromthe invention is described in U.S. Pat. No. 5,487,127, issued Jan. 23,1996 to Gronet, et al., and is hereby incorporated by reference in itsentirety.

A dielectric barrier discharge (DBD) lamp assembly 150 is disposedbetween the radiant heat assembly 106 and the substrate support 108. TheDBD lamp 150 comprised of a grounded electrode which is the interiorface of the radiant heat assembly 106, a high voltage electrode 202insulated from the chamber body (insulation not shown in the Figures),and a dielectric barrier 114. In one embodiment, the dielectric barrieris a quartz window for the radiant heat assembly 220. The DBD lampassembly 150 generates short wavelength radiant energy which is used topromote substrate processing. A discharge space 152 is defined in theDBD lamp assembly 150 into which a discharge gas is supplied. The powersupply 156 energizes the discharge gas present in the discharge space152. The energized discharge gas emits an ultraviolet (UV) radiation,thereby irradiating the substrate with a higher flux of UV radiationthan what would be provided by the heat assembly 106 alone. In oneembodiment, the radiation energy generated through the DBD lamp assembly150 includes combined UV radiation and IR radiation having a wavelengthfrom around 100 nm to 4000 nm. In another embodiment, the radiationenergy generated by the DBD lamp assembly 150 has an UV radiation and/orIR radiation with a wavelength around 100 nm to 1500 nm.

The substrate support assembly 108 is disposed on the bottom 110 of thechamber 102 to receive the substrate 140 positioned thereon. Thesubstrate support assembly 108 may be configured to rotate the substrate140, thereby allowing the substrate 140 to be conformally heated by theradiant energy generated by the radiant heat assembly 106 and DBD lampassembly 150.

A circuit arrangement 154 couples to the dielectric barrier dischargelamp assembly 150 by a power source 156. The circuit arrangement 154 isadapted to provide power to the DBD lamp assembly 150. In operation, thevoltage applied to the DBD lamp assembly 150 establishes an electricfield to enable the generation of radiant energy by the DBD lampassembly 150 which promotes the reactions and photochemical process onthe surface of the substrate 140, thereby allowing the thermalprocessing on the substrate 140. Additionally, the radiant heat assembly106 may have a separate circuit arrangement (not shown) to power thelamps 106 which generate the thermal energy. The thermal energygenerated from the radiant heat assembly 106 radiates the surface of thesubstrate 140 to provide sufficient heat energy. The thermal energygenerated from the radiant heat assembly 106 may also augment theradiant energy generated from the DBD lamp 150 which radiates thesurface of the substrate 140 to activate the surface of the substrate140, thereby promoting the reaction on the surface of the substrate 140.

An atmosphere control system 164 is coupled to the interior volume 120of the chamber body 102. The atmosphere control system 164 includesthrottle valves and vacuum pumps for controlling chamber pressure. Theatmosphere control system 164 may additionally include gas sources forproviding process or other gases to the interior volume 120. In oneembodiment, the atmosphere control system 164 provides process gases forthermal deposition process. In another embodiment, the atmospherecontrol system 164 provides gases for annealing processes. The dischargegas in the region 152 may be supplied by the atmosphere control systemor a separate inlet (not shown).

FIG. 2 is one embodiment of a DBD lamp assembly 150 disposed in athermal processing chamber 200. The DBD lamp assembly 150 includes afirst electrode 220, a dielectric barrier 114, and a second electrode202. The first electrode 220 is grounded. The second electrode 202 isinsulated from the chamber body (insulation not shown in the Figures).The dielectric barrier 114 is disposed between the first electrode 220and the second electrode 202 and maintains the first electrode 220 andthe second electrode 202 in a spaced-apart relation. The DBD lampassembly 150 is configured to generate radiant energy to energize thesurface of the substrate 140. In one embodiment, the first electrode 220is the radiant heat assembly 106 described in FIG. 1. In anotherembodiment, the first electrode 220 may have other configuration,suitable for providing radiant energy to the substrate.

The second electrode 202 is an electrical conductive material configuredto deliver electricity and allow the generated radiant energy to passtherethrough. In one embodiment, the second electrode 202 is a wiregrid, a metal mesh, a perforated metal, an expanded metal, or otherconductive web material. Suitable materials of the second electrode 202include, but not limited to, aluminum, stainless steel, tungsten,copper, molybdenum, nickel, and other metal material. In anotherembodiment, the second electrode 202 may be a conductive material asdescribed above but coated with a dielectric layer. In yet anotherembodiment, the second electrode 202 may be a conductive material coatedonto a dielectric layer in an open pattern. The dielectric layer may bea transparent dielectric layer or a sufficiently thin dielectric layerthat facilitates the transmission of the radiation energy. Suitablematerials of the dielectric layer include, but not limited to MgO, SiO₂,Y₂O₃, La₂O₃, CeO₂, SrO, CaO, MgF₂, LiF₂, and CaF₂, among others. Theconductive material could be indium tin oxide (ITO), SnO₂, W, Mo, Cu, oranother metal.

The dielectric barrier 114 acts as a current limiter during energizingprocess and prevents the radiant energy from transitioning to asustained arc discharge. In one embodiment, the dielectric barrier 114is a transparent dielectric material that allows the radiant energy tobe emitted therethrough. In another embodiment, the dielectric barrier114 is a transparent dielectric material such as glass, quartz,ceramics, or other suitable polymers. In yet another embodiment, thedielectric material is the quartz window 114, as described in FIG. 1.

A discharge space 212 is defined between the dielectric barrier 114 andsecond electrode 202 in the processing chamber 200. A discharge gas issupplied into the discharge space 212. The discharge space 212 has aselected discharging distance 210 creating a discharge volume to allowsufficient collisions among the electrons and the discharge gas executedin the discharge space 212. The discharge volume is configured tosufficiently promote the collisions of the electrons and the dischargegas so that excited species, including excimers, may be created, therebygenerating the UV radiation as desired. In one embodiment, the dischargedistance 210 is selected within an adequate range to promote thecollisions in the discharge space 212. In another embodiment, thedischarge distance 210 is selected between about 0.1 centimeters andabout 100 centimeters, for example, between about 2 centimeters andabout 20 centimeters. Additionally, the pressure in the discharge space212 may be maintained at between about 0.5 Torr and about 600 Torr.

The collision of electrons with the discharge gas provides energy to thedischarge gas creating reactive species including discharge plasmaspecies and excimers. Some energized reactive species emit radiationenergy, e.g, photons, creating UV radiation emitting to the surface ofthe substrate 140. The surface of the substrate 140 absorbs the photons,activating the surface of the substrate 140 into an energetic state. Theenergized surface of the substrate 140 promotes the reaction of thesubstrate, for example, an annealing process or a surface rearrangement.In one embodiment, the discharge gas may be oxygen gas (O₂). In anotherembodiment, the discharge gas may be a gas mixture selected from a groupincluding oxygen gas (O₂) and noble gases, such as xenon gas (Xe),krypton gas (Kr), argon gas (Ar), neon gas (Ne), helium gas (He) and thelike. In yet another embodiment, the discharge gas may be a gas mixtureincluding at least one of oxygen gas (O₂), noble gases, a halogencontaining gas, fluorine, bromine, chlorine gas, an iodine containinggas, H₂O, and NH₃.

A process gas may be supplied into the interior volume 120 of theprocess chamber 200 to optimize the process conditions as required. Theprocess gas supplied into the interior volume 120 is excited by the UVradiation from the DBD lamp assembly 150, creating excited gas speciesto the surface of the substrate 140. The excited gas species as well asthe reactive species energized from the discharge gas activate thesurface of the substrate into an energetic state, thereby triggering thephotochemical reaction on the substrate 140 and allowing the substrate140 being intensively and uniformly processed. As the embodimentdepicted in FIG. 2, as the second electrode 202 is configured to be ametal mesh or wire grid material, the discharge gas may flow though thesecond electrode 202 and across to the substrate surface 140 as theprocess gas. In another embodiment, the process gas may be differentfrom the discharge gas individually supplied into the surface of thesubstrate 140. The process gas may include at least one of oxygen gas(O₂), noble gases, a halogen containing gas, H₂O, N₂O, N₂ or NH₃.

A circuit arrangement 204 applies an operating voltage from a powersource 250 to the first electrode 220 and the second electrode 202. Inoperation, the voltage applied to the two electrodes 220, 202establishes an electric field that promotes the electrons being collidedin the discharge space 212. The electron collision generates an energyto the discharge gas in the discharge space 212, thereby energizing thedischarge gas into an excited state which typically refers as reactivespecies, discharge species, or excimers. The reactive speciessubsequently recombine to release energy as a form of radiation, e.g.,UV photons. The radiant energy 208 travels to surface of the substrate140 promoting the photochemical process and reaction. The UV radiation208 yields higher photon energies, thereby facilitating photochemicalreaction occurred on the surface of the substrate 140, thus enabling thesubstrate to be uniformly processed. Additionally, the radiant heatassembly 106 also generates thermal radiation energy 206 diffusing aswell as the radiant energy 208 to the surface of the substrate 104,thereby creating a combined IR and UV radiation to promote the substratereaction. In one embodiment, the UV radiation 208 generated by the DBDlamp assembly 150 has a wavelength about 100 nm to about 400 nm. Inanother embodiment, the combined thermal radiation energy 206 and the UVradiation 208 generated by the DBD lamp assembly 150 and radiant heatassembly 106 has a combined IR and UV radiation at a wavelength about100 nm to about 4000 nm.

The voltage applied by the circuit arrangement 204 from the power supply250 is selected so that an electric field may be established that issufficient to generate energy as described above. In one embodiment, thevoltage may be applied between about 100 Volts or about 20,000 Volts,for example, about 1,000 Volts or about 5,000 Volts.

FIG. 3 depicts one embodiment of a DBD lamp assembly 150 in a thermalprocessing chamber 300. The DBD lamp assembly 150 includes a firstelectrode 320, a second electrode 302, and a dielectric barrier 114. Thefirst electrode 320 is grounded. The second electrode 302 is insulatedfrom the chamber body (insulation not shown in the Figures). Thedielectric barrier 114 is disposed between the first electrode 320 andthe second electrode 302 and maintains the first electrode 320 and thesecond electrode 302 in a spaced-apart relation. A transparent window304 is disposed below the DBD lamp assembly 150. It is noted that theembodiment described in FIG. 3 is substantially similar as theembodiment described in FIG. 2 except the transparent window 304 may beoptionally disposed below the DBD lamp assembly 150.

The transparent window 304 disposed in the process chamber 300 isolatesthe DBD lamp assembly 150 from an interior volume 318. The isolated DBDlamp assembly 150 allows the discharge gas in the discharge space 314 tobe contained within the DBD lamp assembly 150, thereby minimizing usageof the discharge gas. The transparent window 304 also isolates the DBDlamp assembly 150 from the interior volume 318 of the processing chamber300, thereby prevents the unwanted plasma species and other dischargespecies exiting in the DBD lamp assembly 150. The undesired sputteredmaterial associated with the DBD lamp assembly 150, e.g., particles orcontaminants sourced from the bombardment of the dielectric materials,may also beneficially prevent from entering into the interior volume 318of the processing chamber 300. Additionally, the isolated dischargespace 314 prevents process gases supplied to the interior volume 318from mixing with the discharge gas in the discharge space 314, therebyoptimizing the selection of the process gas and discharge gas forvarious process requirements. In one embodiment, the process gas may bethe same as the discharge gas. In another embodiment, the process gassupplied into the interior volume 318 is selected from a group includingoxygen gas (O₂), noble gases, a halogen containing gas, H₂O, N₂O, N₂ andNH₃.

The transparent window 304 is fabricated form a material selected topermit radiant energy generated in the DBD lamp assembly 150 and theradiant heating assembly 106 to pass therethrough without significantenergy loss. In one embodiment, the transparent window 304 is fabricatedfrom at least one of quartz, glass substrate, MgF₂, CaF₂, or LiF₂.

FIG. 4 depicts another embodiment of an internal isolated dielectricbarrier discharge lamp assembly 150 in a thermal processing chamber 400.A radiant heat assembly 106 including honeycomb tubes 160 and a quartzwindow 114, as described in FIG. 1, is disposed on the top surface ofthe process chamber 400. The radiant heat assembly 106 and thedielectric barrier discharge lamp assembly 150 provide radiant energythrough to the substrate surface 140. In one embodiment, the radiantenergy generated from the radiant heat assembly 106 has IR and/or alonger wavelength UV radiation. In another embodiment, the radiantenergy generated from the radiant heat assembly 106 has a wavelength ofabout 400 nm to about 4000 nm.

The dielectric barrier discharge lamp assembly 150 is disposed below theradiant heat assembly 106 including a first electrode 402, a secondelectrode 408, and dielectric barriers 404 and 406. The DBD lamp 150 maybe isolated from the walls 104 of the processing chamber 400 by segments(not shown) or may have one of its electrodes grounded. In oneembodiment, the electrodes 402, 408 are electrical conductive materialconfigured to deliver electricity and allow radiant energy to begenerated upon application of a voltage. In another embodiment, theelectrodes 402, 408 are wire grids, metal meshes, a perforated metal, anexpanded metal, or other conductive web materials. Suitable materials ofthe electrodes 402, 408 include, but not limited to, aluminum, stainlesssteel, tungsten, copper, molybdenum, nickel, and other metal alloy. Inanother embodiment, the electrodes 402, 408 may be a conductive materialas described above but coated with a dielectric layer. In yet anotherembodiment, the electrodes 402, 408 may be a conductive material coatedonto a dielectric layer like 404 or 406. The dielectric layer may be atransparent layer or a dielectric layer having a sufficient thinthickness that facilitates the transmission of the radiation energy.Suitable materials of the dielectric layer include, but are not limitedto MgO, SiO₂, Y₂O₃, La₂O₃, CeO₂, SrO, CaO, MgF₂, LiF₂, and CaF₂, amongothers. The conductive material may be a metal already mentioned as wellas indium tin oxide (ITO), or SnO₂.

The dielectric barriers 404 and 406 are disposed between the firstelectrode 402 and the second electrode 408. The dielectric barriers 404,406 act as current limiters during the energizing process and preventthe radiant energy from transitioning into a sustained arc discharge. Inone embodiment, the dielectric barriers 404, 406 are transparentdielectric materials that allow the radiant energy to be emittedtherethrough. In another embodiment, the dielectric barriers 404, 406are transparent dielectric materials such as glass, quartz, MgF₂, CaF₂,and LiF₂, ceramics, or other suitable polymers.

The dielectric barrier 406 may also serve as a transparent window. Thetransparent window 406 is fabricated from a material facilitatestransfer of radiant energy generated from the DBD lamp assembly 150 andradiant heat assembly 106 to the substrate surface 140 withoutsignificant energy loss. In one embodiment, the transparent window isfabricated from quartz, glass substrate, MgF₂, CaF₂, and LiF₂, amongothers. Alternatively, in embodiments that two electrodes 402, 408 arecoated with transparent dielectric layers, the transparent window 406and the dielectric layer 404 may be omitted and replaced by the coatedtransparent dielectric layers as needed.

A discharge space 418 is defined between the dielectric barrier 404 andtransparent window 406 in the processing chamber 400. A discharge gas issupplied into the discharge space 418. The discharge space 418 has aselected discharging distance 410 creating a discharge volume to allowsufficient collisions among the electrons and the discharge gas in thedischarge space 418. The discharge volume is configured to sufficientlypromote the collisions of the electrons and the discharge gas so thatexcited species, including excimers, are created thereby generating theUV radiation as desired. In one embodiment, the discharge distance 410is selected within an adequate range to promote the collisions in thedischarge space 418. In another embodiment, the discharge distance 410is selected between about 0.1 centimeters and about 100 centimeters, forexample, between about 2 centimeters and about 20 centimeters.Additionally, the pressure in the discharge space 418 may be maintainedat between about 0.5 Torr and about 600 Torr.

The collision of electrons in the discharge space 418 provides energy tothe discharge gas creating reactive species including discharge plasmaspecies and excimers. The reactive species emit radiation energy, e.g,photons, creating UV radiation emitting to the surface of the substrate140. As the transparent window 406 is disposed in the DBD lamp assembly150, the discharge gas is isolated from exiting the DBD lamp assembly,thereby allowing a process gas being individually supplied to theinterior volume 420 of the processing chamber 400. The UV radiationgenerated from the DBD lamp assembly 150 activates the process gas inthe interior volume 420, creating the reactive species. The surface ofthe substrate 140 absorbs the reactive species generated from theprocess gas, thereby promoting the photochemical process and reaction ofthe substrate, for example, an oxidation or nitridation process.Additionally, the radiant energy generated from the radiant heatassembly 106 radiates to the substrate surface, thereby generating acombined IR and UV radiation to activate the surface of the substrateand allow a uniform and intensive process reaction on the substrate 140.In one embodiment, the discharge gas and process gas may be oxygen gas(O₂). In another embodiment, the discharge and process gas may be a gasmixture selected from a group including oxygen gas (O₂) and noble gases,such as xenon gas (Xe), krypton gas (Kr), argon gas (Ar), neon gas (Ne),helium gas (He) and the like. In yet another embodiment, the dischargegas and process gas may be a gas mixture including at least one ofoxygen gas (O₂), noble gases, a halogen containing gas, fluorine,bromine, chlorine gas, an iodine containing gas, H₂O, N₂O, N₂ and NH₃.In still another embodiment, the process gas may be selected to bedifferent from the discharge gas as needed.

A circuit arrangement 412 applies an operating voltage from a powersource 450 to the first electrode 402 and the second electrode 408. Inoperation, the voltage applied to the two electrodes 402, 408establishes an electric field that promotes the electrons being collidedin the discharge space 418. The electron collision generates an energyto the discharge gas in the discharge space 418, thereby energizing thedischarge gas into an excited state which is typically referred to asexcited species, discharge species, or excimers. Some of these speciessubsequently relax to the ground state by releasing energy in the formof radiation 416, e.g., photons and/or UV radiation, from the DBD lampassembly 150. The radiant energy 416 travels to surface of the substrate140 promoting the photochemical process and reaction. The UV radiation416 yields higher photon energies, thereby facilitating photochemicalreaction occurring on the surface of the substrate 140, thus enablingthe substrate to be uniformly thermal processed. Additionally, theradiant heat assembly 106 also generates thermal radiation energy 410radiating as well as the radiant energy 416 to the surface of thesubstrate 104, thereby creating a combined IR and UV radiation topromote the substrate reaction. In one embodiment, the UV radiation 416generated by the DBD lamp assembly 150 has a wavelength about 100 nm toabout 400 nm. In another embodiment, the combined radiation energy 414and the UV radiation 416 generated by the DBD lamp assembly 150 andradiant heat assembly 106 has a combined IR and UV radiation at awavelength about 100 nm to about 4000 nm.

The voltage applied by the circuit arrangement 412 through the powersupply 450 is selected so that a sufficient electric field may beestablished to generate energy. In one embodiment, the voltage may beapplied between about 100 Volts and about 20,000 Volts, for example,about 1,000 Volts and about 5,000 Volts.

The transparent window 406 disposed in the process chamber 400 isolatesan internal isolated discharge space 418 from an interior volume 420.The isolated discharge space 418 allows the discharge gas be containedwithin the DBD lamp assembly 150, thereby minimizing usage of thedischarge gas. The transparent window 406 also isolates discharge gasfrom the interior volume 420 of the processing chamber 400, therebyprevents the unwanted plasma species and other discharge species exitingin the DBD lamp assembly 150. The undesired sputtered materialassociated with the DBD lamp assembly 150, e.g., particles orcontaminants sourced from the bombardment of the dielectric materials,may also beneficially prevent from entering into the interior volume 420of the processing chamber 400. Additionally, the isolated dischargespace 418 prevents process gases supplied to the interior volume 420from mixing with the discharge gas, thereby optimizing the selection ofthe process gas and discharge gas for various process requirements. Inone embodiment, the process gas may be the same as the discharge gas. Inanother embodiment, the process gas supplied into the interior volume318 is selected from a group including oxygen gas (O₂), noble gases, ahalogen containing gas, H₂O, N₂O, N₂ and NH₃.

FIG. 5 depicts another embodiment of an internal isolated DBD lampassembly 150 in a thermal processing chamber 500. A radiant heatassembly 106 including honeycomb tubes 160 and a quartz window 114, asdescribed in FIG. 1, is disposed on the top surface of the processchamber 500. The radiant heat assembly 106 provides radiant energy 508through the DBD lamp assembly 150 to the substrate surface 140. In oneembodiment, the radiant energy 508 generated from the radiant heatassembly 106 has IR and/or a longer wavelength of UV radiation. Inanother embodiment, the radiant energy 508 generated from the lampassembly 106 has a radiation at wavelength about 400 nm to about 4000nm.

The DBD lamp assembly 150 includes a first electrode 502 and a secondelectrode 504. The electrodes 502, 504 include a dielectric layer 520coated on a conductive cylinder 522 having a hollow passage 524 in thecenter of the cylinder 522, thereby allowing a coolant fluid to flowtherefrom. In one embodiment, the electrodes 502, 504 are configured anarray of two rows positioned parallel to each other. In anotherembodiment, the electrodes 502, 504 may be two conductive sheetspositioned parallel to each other. In yet another embodiment, theelectrodes 502, 504 are electrical conductive material configured todeliver electricity and allow radiant energy to be generated uponapplying a voltage. Suitable materials of the electrodes include, butnot limited to, aluminum, stainless steel, nickel, and other metalalloy.

The dielectric layer 520 coated on the cylinder 522 is a dielectricmaterial. The dielectric layer may be a transparent layer or adielectric having a sufficient thin thickness that facilitates theemission the radiation energy. In one embodiment, the dielectricmaterial is selected from a group including MgO, SiO₂, Y₂O₃, La₂O₃,CeO₂, SrO, CaO, MgF₂, LiF₂, and CaF₂, among others. Since there can belarge spaces between the electrodes, the requirement of transparency forthe dielectric may be relaxed.

The coolant fluid 524 may be supplied to the hollow passage 524 of thecylinder 522 to regulate the temperature of the cylinder 522 as need. Inone embodiment, the coolant fluid may be deionized water or othersuitable heat transfer medium.

A discharge space 526 is defined between the dielectric barrier 502 andthe second electrode 504. A discharge gas is supplied into the dischargespace 526. The discharge space 526 has a selected discharging distance514 creating a discharge volume to allow sufficient collisions among theelectrons and the discharge gas in the discharge space 526. In oneembodiment, the discharge distance 514 is selected within an adequaterange to promote the collisions in the discharge space 526. In anotherembodiment, the discharge distance 514 is selected between about 0.1centimeters and about 100 centimeters, for example, between about 2centimeters and about 20 centimeters. Additionally, the pressure in thedischarge space 526 may be maintained at between about 0.5 Torr andabout 600 Torr.

The collision of electrons in the discharge space 526 provides energy tothe discharge gas creating reactive species including discharge plasmaspecies and excimers. In one embodiment, the discharge gases may beoxygen gas (O₂). In another embodiment, the discharge gas may be a gasmixture selected from a group including oxygen gas (O₂) and noble gases,such as xenon gas (Xe), krypton gas (Kr), argon gas (Ar), neon gas (Ne),helium gas (He) and the like. In yet another embodiment, the dischargegas may be a gas mixture including at least one of oxygen gas (O₂),noble gases, a halogen containing gas, fluorine, bromine, chlorine gas,an iodine containing gas, H₂O, and NH₃.

A transparent window 516 may be optionally disposed below the secondelectrode 504. The transparent window 506 is fabricated from a materialthat facilitates transfer of radiant energy generated from the DBD lampassembly 150 to the substrate surface 140 without significant energyloss. In one embodiment, the transparent window is fabricated fromquartz, glass substrate, MgF₂, CaF₂, and LiF₂, among others.

A circuit arrangement 506 applies an operating voltage from a powersource 550 to the first electrode 502 and the second electrode 504. Inoperation, the voltage applied to the two electrodes 502, 504establishes an electric field that promotes the electrons being collidedin the discharge space 526. The electron collision generates an energyto the discharge gas in the discharge space 526, thereby energizing thedischarge gas into an excited state which typically refers as excitedspecies, discharge species, or excimers. The excited speciessubsequently relax to the ground state thereby releasing energy as aform of radiation 510, e.g., photons and/or UV radiation, from the DBDlamp assembly 150. As the transparent window 516 is disposed in the DBDlamp assembly 150, the discharge gas is isolated from exiting the DBDlamp assembly, thereby allowing a process gas being individuallysupplied to the interior volume 530 of the processing chamber 500. TheUV radiation generated from the DBD lamp assembly 150 activates theprocess gas in the interior volume 530, creating the reactive species.The surface of the substrate absorbs the reactive species generated fromthe process gas, thereby promoting the photochemical process andreaction of the substrate, for example, an oxidizing or oxynitridatingprocess. Additionally, the radiant heat assembly 106 also generatesthermal radiation energy 508 diffusing along with the radiant energy 510to the surface of the substrate 104, thereby creating a combined IR andUV radiation to promote the substrate reaction. In one embodiment, theUV radiation 510 generated by the DBD lamp assembly 150 has a wavelengthabout 100 nm to about 400 nm. In another embodiment, the combinedradiation energy 508 and the UV radiation 510 generated by the DBD lampassembly 150 and radiant heat assembly 106 has a combined IR and UVradiation at a wavelength about 100 nm to about 4000 nm.

The voltage applied by the circuit arrangement 506 through the powersupply 550 is selected so that a sufficient electric field may beestablished to energize the discharge gas. In one embodiment, thevoltage may be applied between about 100 Volts or about 20,000 Volts,for example, about 1,000 Volts or about 5,000 Volts. More complicatedelectrode powering arrangements may be employed whereby power may notuniformly applied to the entire electrode set but alternated rapidlyamongst subsets of electrodes to improve the uniformity of the DBD lampassembly

The transparent window 516 disposed in the process chamber 500 isolatesthe DBD lamp assembly 150 from an interior volume 530. The isolated DBDlamp assembly 150 allows the discharge gas in the discharge space 526 becontained within the DBD lamp assembly 150, thereby minimizing usage ofthe discharge gas. The transparent window 504 also isolates dischargegas from the interior volume 530 of the processing chamber 500, therebyprevents the unwanted plasma species and other discharge species exitingin the DBD lamp assembly 150. The undesired sputtered materialassociated with the DBD lamp assembly 150, e.g., potential particles orcontaminate sourced from the bombardment of the dielectric materials,may also beneficially prevent from entering into the interior volume 530of the processing chamber 500. Additionally, the isolated DBD lampassembly 150 prevents process gases supplied to the interior volume 530from mixing with the discharge gas, thereby optimizing the selection ofthe process gas and discharge gas for various process requirements. Inone embodiment, the process gas may be the same as the discharge gas. Inanother embodiment, the process gas supplied into the interior volume530 is selected from a group including oxygen gas (O₂), noble gases, ahalogen containing gas, H₂O, N₂O, N₂ and NH₃

FIG. 6 depicts another embodiment of an internal isolated dielectricbarrier discharge lamp assembly 150 in a thermal processing chamber 600.The process chamber 600 includes a chamber lid 602 mounted on the top ofthe chamber 600. A heat assembly 622 is embedded in the substratesupport 108 disposed on the bottom 110 of the process chamber 600. Adielectric barrier discharge lamp assembly 150 is disposed below thechamber lid 602 including a first electrode 606, a second electrode 612,and a dielectric barrier 608. Alternatively, the first electrode 606 maybe configured to be the chamber lid 602 of the processing chamber 600.In one embodiment, the electrodes 606, 612 are electrical conductivematerial configured to deliver electricity and allow radiant energy tobe generated upon application of a voltage. In another embodiment, theelectrodes are wire grids, metal meshes, perforated metals, expandedmetals, or other conductive web materials. Suitable materials of theelectrodes 606, 612 include, but not limited to, aluminum, stainlesssteel, nickel, and other metal alloy. In yet another embodiment, theelectrodes 606, 612 may be a conductive material coated with adielectric layer. Suitable materials of the dielectric layer include,but not limited to, MgO, SiO₂, Y₂O₃, La₂O₃, CeO₂, SrO, CaO, MgF₂, LiF₂,and CaF₂, among others.

An interior space 616 is created between the chamber lid 602 and thedielectric barrier discharge lamp assembly 150. The interior space 616has a distance 604 configured to maintain the chamber lid 602 and DBDlamp assembly 150 in a spaced-apart relation. The distance 604 isselected to prevent contact between the chamber lid 602 and the DBD lampassembly 150 during processing. In one embodiment, the distance 604 isselected between 0.1 to 200 millimeter, for example 1 to 60 millimeter.

A cooling fluid may be optionally supplied to the interior space andremove the heat generated by the DBD lamp assembly 150. In oneembodiment, the cooling fluid may be deionized water or other suitableheat transfer medium.

The dielectric barrier 608 is disposed below the first electrode 606 andthe second electrode 612. The dielectric barrier 608 acts as a currentlimiter during energizing process and prevents the radiant energytransiting into a sustained arc discharge. The dielectric barrier mayallow the radiation energy from the DBD discharge space 620 to transmittherethrough. In one embodiment, the dielectric barrier 608 and/or thefirst electrode 606 may be a reflector configured to reflect theradiation energy from the DBD discharge space 620, thereby maximizingthe radiation energy delivered to the substrate from the DBD assembly150. In another embodiment, the dielectric barrier may be a transparentdielectric layer or a dielectric layer having a sufficient thinthickness that facilitates the transmission of the radiation energy. Inone embodiment, the dielectric barrier 608 is a transparent dielectricmaterial such as glass, quartz, ceramics, or other suitable polymers. Inembodiments where the dielectric barrier 608 is configured as areflector, the dielectric barrier 608 may be constructed as a multilayerdielectric interference film.

A transparent window 610 is disposed between the dielectric barrier 608and the second electrode 612. The transparent window 610 is fabricatedfrom a material which facilitates transfer of radiant energy generatedby the DBD lamp assembly 150 to the substrate surface 140 withoutsignificant energy loss. In one embodiment, the transparent window isfabricated from quartz, glass substrate, MgF₂, CaF₂, and LiF₂, amongothers. Alternatively, in embodiments that two electrodes 606, 612 arecoated with transparent dielectric layers, the transparent window 610and the dielectric layer 608 may be omitted and replaced by the coatedtransparent dielectric layers as needed.

A discharge space 620 is defined between the dielectric barrier 608 andthe transparent window 610. Discharge energy may be supplied into thedischarge space 620. The discharge space 620 has a selected dischargingdistance 614 creating a discharge volume to allow sufficient collisionsbetween the electrons and the discharge gas in the discharge space 620.In one embodiment, the discharge distance 614 is selected within anadequate range to promote the collisions in the discharge space 620. Inanother embodiment, the discharge distance 614 is selected between about0.1 centimeters and about 100 centimeters, for example, between about 2centimeters and about 20 centimeters. Additionally, the pressure in thedischarge space 620 may be maintained at between about 0.5 Torr andabout 600 Torr. In one embodiment, the discharge gases may be oxygen gas(O₂). In another embodiment, the discharge gas may be a gas mixtureselected from a group including oxygen gas (O₂) and noble gases, such asxenon gas (Xe), krypton gas (Kr), argon gas (Ar), neon gas (Ne), heliumgas (He) and the like. In yet another embodiment, the discharge gas maybe a gas mixture including at least one of oxygen gas (O₂), noble gases,a halogen containing gas, fluorine, bromine, chlorine gas, an iodinecontaining gas, H₂O, N₂O, N₂ and NH₃.

A process gas may be supplied into the interior volume 626 of theprocess chamber 600 to optimize the process conditions as required. Inone embodiment, the process gas may be the same gas as the dischargegas. In another embodiment, the process gas may be different from thedischarge gas individually supplied into the surface of the substrate140. The process gas may include at least one of oxygen gas (O₂), noblegases, a halogen containing gas, H₂O, N₂O, N₂ or NH₃.

A circuit arrangement 624 applies an operating voltage from a powersource 650 to the first electrode 606 and the second electrode 612. Inoperation, the voltage applied to the two electrodes 606, 612establishes an electric field that promotes the electrons being collidedin the discharge space 620. The electron collision generates an energyto the discharge gas in the discharge space 620, thereby energizing thedischarge gas into an excited state which typically refers as reactivespecies, discharge species, or excimers. The reactive speciessubsequently recombine to release energy as a form of radiation 618,e.g., photons and/or UV radiation, from the DBD lamp assembly 150. Theradiant energy 618 travels to surface of the substrate 140 promoting thephotochemical process and reaction. As the transparent window 610 may bedisposed in the DBD lamp assembly 150, the discharge gas is isolatedfrom exiting the DMD lamp assembly, thereby allowing the process gasbeing individually supplied to the interior volume 626 of the processingchamber 600. The UV radiation generated from the DBD lamp assembly 150activates the process gas in the interior volume 626, creating thereactive species. The surface of the substrate absorbs the reactivespecies generated from the process gas, thereby promoting thephotochemical process and reaction of the substrate, for example, anoxidizing or nitriding process. In one embodiment, the UV radiation 618generated by the DBD lamp assembly 150 has a wavelength about 100 nm toabout 400 nm. In another embodiment, the UV radiation 618 generated bythe DBD lamp assembly 150 includes a longer wavelength between about 100nm to about 2000 nm.

The transparent window 610 disposed in the process chamber 600 isolatesthe discharge space 620 from an interior volume 626 of the processingchamber 600. The isolated discharge space 620 allows the discharge gasbe contained within the DBD lamp assembly 150, thereby minimizing usageof the discharge gas. The transparent window 610 also isolates dischargegas from the interior volume 626 of the processing chamber 600, therebyprevents the unwanted plasma species and other discharge species exitingin the DBD lamp assembly 150. The undesired sputtered materialassociated with the DBD lamp assembly 150, e.g., potential particles orcontaminate sourced from the bombardment of the dielectric materials,may also beneficially prevent from entering into the interior volume 626of the processing chamber 600. Additionally, the isolated dischargespace 614 prevents process gases supplied to the interior volume 626from mixing with the discharge gas, thereby optimizing the selection ofthe process gas and discharge gas for various process requirements. Inone embodiment, the process gas may be the same as the discharge gas. Inanother embodiment, the process gas supplied into the interior volume626 is selected from a group including oxygen gas (O₂), noble gases, ahalogen containing gas, H₂O, N₂O, N₂ and NH₃

Thus, an apparatus of a thermal processing chamber with a dielectricbarrier discharge lamp assembly and a method for using the same isprovided. The apparatus and method provided herein advantageouslyprovide combined UV and IR radiant energy, thereby allowing thesubstrate to be more efficiently processed as compared to theconventional thermal processing chambers.

While the foregoing is directed to the preferred aspects of theinvention, other and further aspects of the invention may be devisedwithout departing from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

The invention claimed is:
 1. A method for thermally processing asemiconductor substrate in a process chamber, comprising: generating athermal radiation energy at a first wavelength by a radiant heatassembly disposed in a process chamber; and generating a UV radiationenergy at a second wavelength different from the first wavelength by adielectric barrier discharge lamp assembly disposed in the processchamber, wherein the thermal radiation energy from the radiant heatassembly emits through the dielectric barrier discharge lamp assembly,forming a combined radiation energy transmitting onto a substratedisposed in the process chamber.
 2. The method claim 1, wherein thedielectric barrier discharge lamp assembly comprises: a first electrodeand a second electrode, the first and the second electrode in aspaced-apart relation; a dielectric barrier between the first and thesecond electrode; and a discharge space defined between the dielectricbarrier and the second electrode.
 3. The method of claim 2 furthercomprising: supplying a discharge gas within the discharge space.
 4. Themethod of claim 3, wherein the step of supplying a discharge gas furthercomprises: exciting the discharge gas by supplying a voltage to thefirst and second electrodes.
 5. The method of claim 3, wherein thedischarge gas is selected from a group consisting of O₂, Xe, Kr, Ar, Ne,He, halogen containing gas, H₂O and NH₃.
 6. The method of claim 1,wherein the second wavelength of the UV radiation energy generated bythe dielectric barrier discharge lamp assembly is between about 100 nmand about 400 nm.
 7. The method of claim 4, wherein exciting thedischarge gas further comprising: supplying a voltage between about 1000volts and about 500 volts to the first and the second electrodes.
 8. Themethod of claim 3, wherein the dielectric barrier is fabricated from atransparent material selected from a group consisting of glass, quartz,ceramics and polymers.
 9. The method of claim 3, wherein the processchamber comprises: a transparent window disposed below the secondelectrode.
 10. The method of claim 9, wherein the transparent window isfabricated from a material selected from a group consisting of quartz,glass, MgF₂, CaF₂, and LiF₂.
 11. The method of claim 3, wherein thefirst and the second electrodes are wire grids, metal meshes perforatedmetal, expanded metal or conducive web materials.
 12. The method ofclaim 3, wherein the first and the second electrodes are fabricated froma material selected from a group consisting of aluminum, stainlesssteel, tungsten, copper, molybdenum and nickel.
 13. The method of claim3, wherein the discharge space has a discharge distance between about0.1 centimeters and about 100 centimeters.
 14. The method of claim 3further comprising: maintaining a pressure in the discharge space ofbetween about 0.5 Torr and about 600 Torr.
 15. The method of claim 3,wherein the first and the second electrodes include a dielectric layercoated on a conductive cylinder.
 16. The method of claim 15 furthercomprising: flowing a coolant fluid through a hollow passage of theconductive cylinder.
 17. The method of claim 3, wherein the firstelectrode is a lid of the process chamber.
 18. The method of claim 3,further comprising: supplying a process gas to an interior volume of theprocess chamber above the surface of the substrate.
 19. The method ofclaim 1, wherein the radiant heat assembly is configured to provide theradiation energy having the first wavelength between about 400 nm andabout 4000 nm.